Why Is Water Leaking On The Passenger Floor Of My Car?

Reader Question Hi Austin,

I’m from Perth, Western Australia, but i think our cars work the same way over here.

Recently I had the a/c motor replaced in my car. but over the last week quite a lot of water has been leaking into the front passenger side of the car.

I understand that a leaking heater coil is probably responsible for this. What i didn’t know was that it would short out the a/c. Which is did this morning. What i want to know is, do you think the mechanic has any responsibility to re-repair the air conditioning?


Hey there Leanne

I would have your mechanic check to see if your A/C drain is stopped up with leaves and debris. This will cause cold clear A/C water to drain inside the vehicle on the passenger side.

If the water on the floor is green and oily feeling….it could be due to a leaking heater core, and you will be low on antifreeze inside the radiator, but I bet you have a restriction in the A/C drain…which can be easily cleaned with a shot of compressed air.

Austin Davis

Posted in: A/C and Heating

6 Comments on "Why Is Water Leaking On The Passenger Floor Of My Car?"

Trackback | Comments RSS Feed

  1. Nicole Ritchey says:

    Hi, I noticed this article when I was looking for reasons for water on the floor of the car. We own a 93 oldsmobile cutlass and recently we have been having a problem with water appearing on the driver’s side and passenger side, but just on the floor. We have tried rolling up the windows and we seem to get it dry and then there is more leakage. I am going to try the suggestion about spraying the car with a garden hose and see if it is the doors or windows. I had also heard that the problem could be due to a clogged ac drain and I was wondering if anyone has a clue where you could go to find out where the drain would be in your car and how to check it. Please talk to me like I am a total idiot because I know nothing when it comes to cars. But this is something that I really need to do myself because I do not have the money to get it fixed. I have also encountered a bunch of comments on other websites where people who have taken their cars to mechanics for this problem and the mechanic replaces the windshield or the sealant on the doors and then they still have the problem with the leaking. Also some articles mentioned drains on the doors for something (I don’t know if it was rain or something internal in the car) and I was wondering if anyone has a guess of where those would be. All of the posts that I saw were about newer cars, so I am not sure if that is something that is on older cars or not. I have also been having a problem with rust around the muffler and I could that be leading to a leak. The leak is only on the front driver’s side and passenger side floors and there is no leak under the car. I would truly appreciate anything that you can tell me!

    • Austin says:

      If the water is cold and clear and has no smell or oily feel to it, yes it could very well be a clogged AC drain. The best thing to do is visit your local fast lube mechanic and ask them if they can blow compressed air into your AC drain hole located under the vehicle on the passenger side. If you are not mechanical….it would be a waste of time to try and explain to you how to do this simple job. Just pay them $30 or what ever to blow out the drain and clear any leaves or debris that might be clogging it. Worst case scenario is the dashboard has to be taken out and the AC evaporator case inside has to be manually cleaned of debris….BIG job, hopefully a good shot of compressed air will clear a problem. With the AC on and engine running, you should see drips of clear water under the vehicle on the passenger side puddle on the ground….that is normal.

  2. Lauren says:

    I have a 2003 Toyota Matrix and recently got the catalitic converter changed out on it as well as the surpenteen belt, now there is water leaking all over the passenger side floor. The water looks greenish, but it has been raining a lot lately too. What can I do to stop this???

    • Austin says:

      Check the antifreeze in your radiator, if it’s low and the liquid on the floor feels kinda greasy then you hve a heater core leak. It’s like a small radiator inside the dashboard. You can have the heater hoses cut and spliced together to bypass the leaking heater core if you are on a budget…there will be no heat coming out of the heater until you replace the core.

  3. 2002 sportage. Water on the Drivers side floor after a harder than average rain, why?

    • admin says:

      I would be suspect of a leaking windshield. You might want to get a water hose and spray your windshield around the edges where the rubber sealer holds it to the vehicle body and see if you can duplicate the problem. You might have to call a windshield company and see if they can reseal it or if the entire windshield has to be replaced.

Got Something to Say?